In a shunt-wound generator, like the one shown in figure 1-16, the field coils consist of many turns
of small wire. They are connected in parallel with the load. In other words, they are connected across the
output voltage of the armature.
Figure 1-16.Shunt-wound generator.
Current in the field windings of a shunt-wound generator is independent of the load current (currents
in parallel branches are independent of each other). Since field current, and therefore field strength, is not
affected by load current, the output voltage remains more nearly constant than does the output voltage of
the series-wound generator.
In actual use, the output voltage in a dc shunt-wound generator varies inversely as load current
varies. The output voltage decreases as load current increases because the voltage drop across the
armature resistance increases (E = IR).
In a series-wound generator, output voltage varies directly with load current. In the shunt-wound
generator, output voltage varies inversely with load current. A combination of the two types can
overcome the disadvantages of both. This combination of windings is called the compound-wound dc
Compound-wound generators have a series-field winding in addition to a shunt-field winding, as
shown in figure 1-17. The shunt and series windings are wound on the same pole pieces.